Epson Multi-mode Data Controller MFJ-1278B User Manual

Page 169

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MFJ-1278B MULTI-MODE ADVANCED OPERATION

6.

Restrict your use of beacon transmissions as much as possible. If you MUST use a
beacon, keep it short and keep the repetition rate as low as possible. More than once a
minute is definitely too frequent. once or twice in 10 minutes is more polite. Do not
allow your beacons to continue if you are not in attendance. Nobody wants to connect
to you just to be ignored.


7.

If your radio allows you to select the AGC time constant (fast or slow AGC), set it to
the fastest setting available to you.

If you cannot select fast AGC, it may be advantageous under some circumstances to
partially defeat the AGC function by reducing RF gain and increasing AF gain. The
demodulator in the MFJ-1278B is extremely insensitive to absolute audio level. It will
function properly with input levels from the low hundreds of millivolts up to many tens
of volts. Thus, the variation in audio level produced by partially defeating the AGC
system will not degrade the modem's ability to copy. The limiting factor on the high
end is usually the ability of the receiver output stage to produce the voltage without
clipping. The limiting factor on the low end is the hundred millivolts or so required to
exceed the MFJ-1278B's digital system noise seen at the demodulator input.

MFJ-1278B KISS MODE, TNC-2 MODE, HOST MODE

One unique feature offered by the MFJ-1278B is that it can be switched into KISS mode to
run programs such as TCP/IP, or it can be converted into a "like-TNC-2" controller. Once
MFJ-1278B is converted, it can run any firmware written for the TNC-2, such as
NET/ROM™ , THE NET™ and other firmwares for the TNC2 & clones. The procedure to
convert the MFJ-1278B into a "like-TNC-2" is described in Appendix E in the instruction
manual.

Host Mode installed in the MFJ-1278B requires a special terminal program to operate.
Documentation for Host Mode is available on disk from MFJ upon request.

KISS INTERFACE FOR TCP/IP

The KISS interface is installed in firmware of the MFJ-1278B. Additional modifications or
replacement of firmware is not necessary.

KISS enables the MFJ-1278B to act as a modem for a host computer. Turning KISS on
allows the MFJ-1278B to run programs such as TCP/IP, MSYS and other programs which
use the Serial Link Interface Protocal (SLIP).

Before enabling KISS, make sure radio baud rate and terminal baud rate are set to the desired
values. The terminal baud rate that's determined at sign on is the same that will be used for
KISS.

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